Another of these factors is infertility. Generally, female gorillas mature at 10â12 years of age (or earlier at 7â8 years) and their male counterparts mature more slowly, rarely strong and dominant enough to reproduce before 15â20 years of age.
A herniated disk, sometimes (incorrectly) called a slipped disk, is a common cause of severe back pain and sciatica. A disk in the lumbar area becomes herniated when it ruptures or thins out, and degenerates to the point that the gel within the disk (the nucleus pulposus) pushes outward.
The close approximation of the sciatic nerve is the reason that increased tone of the piriformis muscle could cause irritation to the sciatic nerve. Irritation to the sciatic nerve in patients with left psoas syndrome often causes pain that radiates down the back of the right leg and stops at the knee.